Preimplantation Genetic Screening and the Success Rate of in vitro Fertilization: A four-year Study in Iranian Population

It is generally accepted that in vitro fertilization (IVF) is one of the most efficient approaches within the context of assisted reproductive technology (ART) to treat infertility. Apparently, high pregnancy rates have become the major index of successful IVF in clinical studies. It is still not clear which certain factors are responsible for IVF success, as various outcomes were obtained in different IVF centers performing IVF in different settings.In this retrospective study, we aimed to address controversies in interpretation of promising results of IVF with respect to preimplantation genetic screening (PGS). Therefore, we built a dataset from related patients. Next, the data was analyzed to find influential factors affecting the success rate of ART cycle in Iranian population.This analysis showed that regardless of PGS indications (ART failures, recurrent miscarriage, chromosomal abnormalities, etc.), pregnancy rate might be influenced by maternal and embryonic factors such as the age of mother and the number and quality of transferred embryos. Furthermore, genotyping of embryos using array comparative genomic hybridization (aCGH) depicted that the highest rate of chromosomal aberrations occurred in the chromosomes 1, 16 and 19 while the lowest frequency was found for chromosomes 11 and 17. Similarly, we detected 463 genetically abnormal embryos by aCGH technique, of which only 41.9% could be detected by fluorescent in situ hybridization (FISH) method, which is conventionally based on probing the chromosomes 13, 18, 21, 22 and X/Y. Taken together, in addition to the aforementioned conventional methods, this study not only highlighted the advantages of aCGH over FISH method in detection of chromosomal abnormalities but also emphasized the importance of genetic abnormality as an indication for determination of IVF success rate.

Keywords:

Preimplantation Genetic Screening , Assisted Reproductive Technology , In Vitro Fertilization , array CGH